/* Copyright (c) 2009, Michael Patraw
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 *     * The name of Michael Patraw may not be used to endorse or promote
 *       products derived from this software without specific prior written
 *       permission.
 *
 * THIS SOFTWARE IS PROVIDED BY Michael Patraw ''AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL Michael Patraw BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
#ifndef BOARD_H
#define BOARD_H

#include <stdbool.h>

#define BOARD_SQUARE(b, x, y) ((b)->squares[(y) * (b)->width + x])

#define BOARD_MAX_WIDTH 21
#define BOARD_MAX_HEIGHT 21

/* The board.
 */
typedef struct board_t {
    int width, height;
    int squares[]; /* C99 Incomplete Type */
} board_t;

/* Square constants.
 */
enum {
    HAS_NOTHING,
    HAS_WALL,
    HAS_OBJECT,
    HAS_IMM_OBJECT
};

/* Valid directions to move on the board.
 */
#define UP (1 << 1)
#define DOWN (1 << 2)
#define LEFT (1 << 3)
#define RIGHT (1 << 4)

/* Returns a board of a specified width and height.
 */
extern board_t * Board_Create(int width, int height);

/* Frees a board.
 */
extern void Board_Destroy(board_t * board);

/* Draws the board to a window with an id.
 */
extern void Board_Draw(board_t * board, unsigned int win_id);

/* Checks if the square is accessible.
 */
extern bool Board_BadLocation(board_t * board, int x, int y);

/* Returns a list of valid directions from a certain square.
 * -1 on no directions.
 */
extern int Board_ValidDirections(board_t * board, int x, int y);

/* Pushes blocks if able, based on directions.
 */
extern void Board_PushDirection(board_t * board, int x, int y, int dir);

/* Steps x and y in a given direction.
 */
extern void Board_StepDirection(int * x, int * y, int dir);

/* Returns the direction based on dx, dy.
 */
extern int Board_GetDirection(int x, int y);


#endif /* BOARD_H */
